Dieseling A Air Rifle, (Pellet Gun)

[billt460]

This is all over the Internet, so I'm not going to post any videos. But if you go to Youtube and punch in, "dieseling a air rifle" you'll get enough on the subject to keep you busy.

Apparently this got started in the UK and France, where air rifles are a lot more popular, because of strict laws governing firearm ownership. What it basically involves is taking a pellet and applying a dab of pure petroleum jelly, (Vaseline), into the hollow base of the pellet itself.

Then inserting it into the barrel and firing it normally. The high compressed air temperature entering the barrel "ignites" the Vaseline giving the pellet more velocity and energy. (Much the same way a Diesel engine operates).

The increase in velocity and energy can be substantial. Some guys are experimenting with other over the shelf combustables like WD-40 and such. This obviously won't work with CO2 powered guns because CO2 is not an accelerant.

I haven't come up with anything that shows seal damage, or anything like that. So I'm going to investigate this a bit more, and "give it a shot" in a couple of my air guns. It does produce a louder crack, similar to a .22, so I'll wait until my next trip to the range.

 

[UncleDave]

Ive got a Beeman standing by.

If this works my main question becomes why didn't I think of it as a kid?

 

[Jdeere562]

Good way to ruin your gun.

 

[billt460]

Back when I was a lot younger, (late 60's), Daisy came out with the "VL-22". It operated on a similar Diesel principal. It required special "caseless ammo" that came in a tube.

It operated on the exact same principal of using the Diesel effect of high compressed air temperature to ignite the propellant that was attached to the back of the pellet.

It was a commercial flop because the ammunition was expensive, and very sensitive to moisture. The propellent also was easily broken off the back of the pellet with any type of rough handling.

Today if you have one with any ammunition for it, they can be quite expensive as a collector piece.

 

[WobblyElvis]

A properly made and "tuned" springer air gun will last a long time as the piston does not slam into the forward end of the compression tube when fired. The weight of the piston and spring as well as the strength of the spring are taken into account so that the piston bounces off a cushion of highly compressed air at the front of the compression tube as the pellet starts to travel down the barrel. Dieseling throws the balance off, subjecting the piston assembly and compression tube to extreme forces. Velocity of the projectile is going to vary all over the place. Fun for a little while. There were guns some made with this in mind but they didn't stay in production for long. I guess they had a high failure rate.

 

[vavavroom]

I can't imagine that not being damaging to the rifling.

 

[oldcodger]

I do not think it will harm the rifling but just about sure it will lead the barrel. Pellets are really soft lead and if you push them hard enough they might strip and leave a deposit of lead in the bore.

 

[billt460]

I can't imagine that not being damaging to the rifling.

Rifling is exposed to heat every time a gun is fired. Be it produced by pneumatic or powder.

 

[vavavroom]

Rifling is exposed to heat every time a gun is fired. Be it produced by pneumatic or powder.

I'm wondering more about combustion byproducts than heat.

 

[Dinoburner]

The cleaning instructions that came my air rifle said to remove any lubricants from the barrel before firing. I did notice when a little kerosene was dabbed on the pellet two things happened. One the report was much louder and two I could feel the piston bounce when the oil lit off. The pellet went through a piece of 3/8 plywood like a 22 short.

 

[joegreen]

Some people have to work with what they have because it’s all that’s allowed.

 

[vavavroom]

Precision air gun barrels are fickle and are affected by just different types of pellets. For example, I never cared for the copper-plated ones some of my friends preferred over plain lead pellets. Even if the copper-plated pellets did offer improved accuracy initially, and I'm not sure about that premise, once the copper had fouled the barrel they were performing worse than lead pellets. If you have a cheap Daisy or Remington just try out Dieseling and find out whether or not it degrades accuracy. Upping fps may not benefit accuracy. At over 900 fps accuracy tends to diminish if I remember that right - and it's been 25 years.

 

[MRC01]

As others have said, here dieseling increases pressure & wear on air rifles which aren't designed for it. We try to avoid that.

Regarding velocity, it is usually beneficial to keep the pellets subsonic, and well below it because the transonic region has inconsistent airflow that impairs accuracy. Assuming sea level standard conditions, speed of sound is roughly 1100 fps, and 85% of that is 935, so 900 fps or lower is a good general rule. Powerful air rifles will require heavier pellets to stay subsonic, which is not only more accurate but also retains more energy downrange and better for hunting.

 

[userfriendly]

I do not think it will harm the rifling but just about sure it will lead the barrel. Pellets are really soft lead and if you push them hard enough they might strip and leave a deposit of lead in the bore.

They do. I use starter pistol blanks behind .177 and .22 pellets, but gotta try the Diesel thing.

 

[barryh]

As others have said, here dieseling increases pressure & wear on air rifles which aren't designed for it. We try to avoid that.

My brother and I used to diesel air rifles over 50 years ago when we were kids. I guess we didn't worry about damage to the rifle because we didn't know any better.